Brake mechanism



May 20, 1941 w. .1. MGCLENAHEN 222422,79()

BRAKE MECHAN I S-f Filed Jan. 20, 1933 C) @Sie 59 l .Il i

INVENTOR.

(Alright J.M :Clend/herzV ATTORNE Patented May 20, 1941 UNITED STATESPATENT OFFICE BRAKE MECHANISM Wright J. McClenahen, Dearborn, Mich.,assignor to Kelsey-Hayes Wheel Company, Detroit, Mich., a corporation ofDelaware Application January 20, 1938, Serial No. 185,958

(Cl. 18S-78) 8 Claims.

'I'his invention relates .generally to vehicle brakes and refers moreparticularly to improvements in the construction of the actuatingmechanism for the brake friction means.

It is one of the principal objects of the present invention to provide avehicle brake with an improved actuating mechanism composed of arelatively few simple parts capable of being inexpensively manufactured,assembled, and installed.

Another advantageous feature of this invention which contributesmaterially to reducing the cost and simplifying assembly of the brakeconsists in the provision of a mechanical actuator provided with anoperating lever having one end freely pivotally connected to thefriction means adjacent one end of the latter and provided with a linkhaving the opposite ends respectively freely pivotally connected to theadjacent end of the friction means and to the operating leverintermediate the ends of the latter.

Still another object of this invention resides in the provision of anactuator wherein the free connections referred to in the precedingparagraph are such as to permit the required movement of the ends of thefriction means into engagement with the drum and to provide foradjusting the friction means relative to the drum without any danger ofthe parts of the actuating mechanism becoming disengaged from each otheror the friction means. v

The foregoing, as well as other objects, will be made more apparent asthis description proceeds, especially when considered in connection withthe accompanying drawing, wherein- Figure l is a side elevational Viewof a brake construction having certain parts broken away for the sake ofclearness;

Figure 2 is a sectional View taken substantially on the plane indicatedby the line22 of Figure 1;

Figure 3 is a sectional view taken substantially on the plane indicatedby the line 3-3 of Figure l; and

Figure 4 is a sectional view taken substantially on the plane indicatedby the line 4-4 of Figure l.

For the purpose of illustrating the present invention, I have selected aband type brake construction having two completely independent brakeoperators for actuation respectively by the service pedal and theemergency brake lever or their equivalents. It will also be noted thatin the brake selected for the purpose of illustration, the actuatorunder control of the service pedal is of the hydraulic type, Whereas,the actumeans is shown in Figure 1 as being in the form of a band I3supported on the backing plate within the drum and having a frictionlining I4 on the exterior surface thereof for engaging the brake flangeIl of the drum. In the present instance, the brake band I3 is anchoredintermediate the ends thereof to the backing plate I2 through the mediumof a centering device I5 comprising a stud I6 and a bell crank I1. Thestud I6 is mounted on the backing plate and the bell crank I1 is mountedfor limited oscillation about the axis of the stud and is provided withan arm I8 extending into a slot I8 formed in the band I3 intermediatethe ends thereof. The bell crank I1. is normally held in a neutralposition wherein the band is centered inthe brake drum by means of theaction of the springs I9' located on opposite ends of the arm I8 of thebell crank.

Upon referring again to Figure 1, it will be noted that the ends of theband are spaced from each other circumferentially of the brake flange IIand that` two independent actuators are provided between said ends forexpanding the brake friction lining I4 on the band into engagement withthe brake flange I I of the drum. The actuator, designated by thereference character 20, is of the hydraulic typev and,4 in the presentinstance, is shown as similar in construction to the one described inthe John William White Patent No. 1,999,675, datedApril 30, 1935. Ingeneral, the hydraulic actuator comprises a chamber 2| communicatingwith a source of fluid under pressure (not shown) and having opposedflexible end walls in the form of diaphragms22 for actuating the pistons23 which, in turn, are connected to the free ends of the brake band. Theconnection between each piston 23 and the adjacent end of the band iseffected by means of a stud 24 having a threaded shank portion extendingfreely into a recess formed in the outer end of the piston and having ahead portion provided with a radial slot therein' for receiving theadjacent edge of a web 25 extending `radially inwardly from the brakeband. In the present instance,

` slot 42 in the outer side edge thereof.

thewebs z5 form-parts of brackets ze having the base portions 2] welded,or otherwise permanent-'1k ly secured, to the inner surfaces of theadjacent between the adjacent sides of the pistons 23, the.

latter are moved outwardly relative to the cylinthe adjacent ends of thebrake band into engagement with the annular brake flange Il on "thedrum. The vadjacent ends of the brake band are moved outwardly intoengagement with the brake flange by the hydraulic actuator against we'action of the spring 28 having the opposite el's receive a portion ofthe web in the manner shown in Figure 2'. In this connection, attentionis also called to the fact that the aforesaid web 251s formed with aninwardly opening slot M in the inner edge thereof and that this slot isadapted tofreely receive the flange Iii on the lever 36.

I Asshown'in Figure l, slotting the-web 25 in the der 28 and effect aVcorresponding movement of manner stated provides an inwardly extendingprojection-45 at the inner side of the flange Il, and this projectioncooperates with the inner wall 46 of v,the slot 44 to preventdisplacement of respectively connected to the adjacent ends ofthe band.This spring 29 acts to return the brale band to its released position inthe drumwhen" the pressure in the chamber 2i is relieved.`A It haspreviously been stated that the threadid th'elever 36 relative to theband in the direction .o f,.:1ength of the lever.y The.. axially spacedside walls ofthe slot 42iin the flange 4l cooperate with .the webto'preventaxial displacement of the lever relative to the brake drumshank portions of the studs freely engage in re` cesses formed in theouter ends of the pistons; 28

, and, in the present instance, each stud isheldrin assembledrelationship with its associatedipistn by means of a nut Sti abuttingthe outer v,en'dlyf the latter piston. The nuts 313 are threadediyengaged with the shank portions of the studs and are Aformed withannular flanges 3l which extend over the opposite ends of the cylinder28; The flanges are provided with angularly Aspaced serrations toprovide for turning the nuts relative to the cylinder 28. Inasmuch asthestuds are prevented from rotation by engagement of the head portionsthereof with the webs -'on the brackets 28, it follows that rotation ofthe nuts inone direction causes the studs to move outwardly relative tothe pistons 23 and to posltion the brake friction means I4 on the bandin closer relationship to the annular brake flange il. Thus, it will beobserved that the clearance between the brake lining I8 on the brakebandA and the annular brake flange i l on the drum may be accuratelyadjusted by manipulating the nuts 3G. The other actuator for the brakeband is'of a mechanical type and is designated in Figure 1 by thereference character 35. The mechanical actuator is shown in the abovefigure as including a lever 35 having one end freely pivotally connectedto one end of the brake band for swinging movement in a plane parallelto the plane'iof rotation of the drum and having the other endoperatively connected to the usual brake actuating cable 37. isconnected to the lever 38 intermediate the ends of the latter by meansof a link 38 so that swinging movement of the lever 3E by the cable 3i;n the direction of the arrow 39 imparts a spreading The other end of thebrake band' action to the adjacent ends of the brake band and serves toexpand the latter into engagement with the brake flange ll of the drum.

As stated above, the brake operating lever 35 is freely pivotallyconnected to one end of the brake band and this is also true of theconnections at opposite ends of the link 38, with theresult that themechanical actuator may be assembled in the minimum length of time. Indetail. the end of the lever 36 connected to the brake band is axiallyoffset in a rearward direction in the mannerlndicated by the referencecharacter 48 and terminates in an axially forwardly projecting flange 4lhaving an outwardly opening The width of the slot 42 in the flange 4l ispredetermined in dependence upon the thickness of the web 25 extendingradially inwardly from the adjacent `=With the above construction, itwill be noted that--tlielever 38 may be readily assembled with-th'erbrakeband by merely'a sliding motion with thelever relative to theassociated web 25 on the bra-ke band. Attention may be called to thefact at this time that' the bottoms 41 of the two slots,

previously described, engage each other and provide afulcrum about whichthe lever 38 is adapted to swing under the action of the brake cable 31.

The end 48 of the link 38 is similarly freely pivotally connected to theweb 25 on the other end ofthe brake band. As shown, the end 48 of thelink is formed with a substantially axially extending flange 49 havingan outwardly opening slot 50 in the outer edge for receiving a portionof the adjacent web 25 on the brake band. The inner edge of this web 25is formed with an .inlwardly opening slot 5I freely receiving a portionof the flange 49 on the end 48 of the link. As in the above describedconnection, the slot 5l in the web extends in a plane parallel to theplane of rotation of the drum. and the slot 50 in the flange 48 on thelink extends in a plane at right angles vltrtheiplane aforesaid, withthe result that the connection functions in the same manner as theconnection previously described to freely connect the end 48v of thelink with the band.

The opposite end of the link 38 is bifurcated and a portion of the lever36 intermedi-ate they and is arcuate to effect a locking engagement in aplane parallel to the plane of rotation of the drum.

From the foregoing, it will be noted that each of the free connectionsinvolved in the mechanical brake mechanism is effected without the useof fastener elements by merely sliding the several parts into`engagement with each other. It will also be noted that the constructionis such that relative movement of the parts into engagement with eachother effects free interlocking connections therebetween capable of thepivotal action required to effectively operate the brake band.

In order to insure maintaining the parts of the mechanicalbrake inassembled relationship to take up any play that may be present in theconnections, I provide a coil spring 51 around the p0rtion of the link38 adjacent the furcations 53. 'I'he coil spring 5'! is placed undercompression with one end engaging suitable ears 58 projecting laterallyfrom opposite sides of the link and with the other end seated in arecess 58 formed in the lever 38 by the portions 60 of the lever. Withthis arrangement, it will be noted that the coil spring 51 alsomaintains the outer ends of the link 38 and azfiavoo -lever 36 intofrictional engagement with the adjacent ends of the brake band when thelatter is expanded by the hydraulic actuator, or when it is adjusted toreduce the clearance between the brake lining H and brake flange.

What l claim as my invention is:

l. In brake mechanism, a brake drum, brake friction means supportedwithin the drum for engagement with the latter and having spaced endsprovided with radially inwardly extending web portions, actuating meansfor the brake friction means including a lever having a transverseportion at one end slotted to receive a portion of the web at one end ofthe friction means with the bottom of the slot abutting a portion of theinner edge of said web to provide a fulcrum for the lever, said lastmentioned web having portions extending atthe radially inner and outersides of the transverse end portion of the lever to prevent displacementof the latter relative to the friction to provide a fulcrum for thelink, said last named web also having portions extending along the randially inner and outer sides of the transverse portion of the link tomaintain the latter in as sembled relation with the friction means, theopposite end of the link abutting the inner edge of 2 the lever at apoint intermediate the ends of the latter and having portions extendingalong oppcl site sides of said lever. v I

2. ln brake mechanism. a brake drum, brake friction means supportedwithin the drum for engagement with the latter and having spaced endsprovided with radially inwardly extending web portions, actuating meansfor the brake friction means including a lever having a transverseportion at one end slotted to receive a porton of the web at one end ofthe friction with the bottom of the slot abutting a portion of the inneredge of said web to provide a inici-umV for the lever, said lastmentioned web having portions e* tending at the radially inner and outersides of the transverse end portion of the lever to prevent displacementof the latter relative to the friction means, a link having a transverseportion slotted having the opposite end pivotally connected to the leverintermediate the ends of the latter, and yieldable means acting tomaintain the freely pivotal connections aforesaid into engagement duringmovement of the brake friction means into engagement with the drum bythe first named actuator.

4. In brake mechanism, a brake drum. brake friction means supportedwithin the drum for engagement with the latter and having spaced ends,an actuator located between the spaced ends and acting upon the latterto move the friction means into engagement with the drum, a, secondactuator for the brake friction means including a lever having one endfreely pivotally and slidably connected to one end of the frictionmeans, a link having the opposite ends respectively freely pivotally andslidably connected to the other end of the friction means and to thelever intermediate the ends of the latter, anda. spring located undercompression between the link and lever urging the latter elements indirections to maintain the connections between the latter and brakefriction means by the rst named actuator. friction means by the firstnamed actuator.

5. n brake mechanism, a brake drum, brake friction means supportedwithin the drum for engagement with the latter and having spaced ends,means located between the spaced ends for adjusting the brake frictionmeans to vary the clearance between the latter and brake drum, actuatingmeans for the brake friction means includlng a lever having one endfreely pivotally and slidably connected to one end of the frictionmeans, a link having one end freely pivotally and slidablg.r connectedto the other end of the friction tl. brake mechanism, a brake drum,brake friction means supported within the drum for engagement with thelatter and having spaced ends, means located between the spaced ends foradjusting the brake friction means to vary the clearance between thelatter and brake drum, an

to receive the web on the other end of the friction means with thebottom of the slot engaging a portion of the inner edge of the web topro di: a iuin crurn for the link, said last named also hat@ ingportions extending along the radially inner and outer sides of thetransverse portion of the link to maintain the latter in assembledrelation with the friction means, the opposite end of the link abuttingthe inner edge of the lever at a point intermediate the endsof thelatter and having portions extending along opposite sides of said lever,and a. compression spring surrounding-the latter end portion of the linkwith one end abutting the inner edge of the lever and -with the oppositeend abutting shoulders on said link.

3. In brake mechanism, a brake drum, brake friction means supportedwithin. the drum for engagement with the latter and having spaced ends.actuating means for the brake friction means located between said endsand eective to move the latter outwardly into engagement with the brakedrum, a second actuator for the brake friction means including a leverhaving one end freely pivotally connected to one end of the frictionmeans, a link having one end freely pivotally connected to the other endof the friction means and intermediate the ends of the latter, andyieldable means for maintaining the slidable connections duringadjustment of the friction means and during actuation of the frictionmeans by the first nam-ed actuator,

7. nbrake mechanism, a brake drum, brake friction means supported withinthe drum for engagement with the latter and having spaced ends providedwith radially inwardly extending web portions, actuating means for thebrake friction means including a lever having a portion at one endextending at substantially right angles to the radially extending webportion at one end of the friction means and slotted to receive aprtionof the latter end of said web with the bottom of Athe slot abutting theedge por'tdon o said end to provide a fulcrum for the lever, said lastnamed web having portions extending at the radially inner and outersides of the right angular end portion of the lever to preventdisplacement of the latter relative to the friction means. and a linkhaving one end freely pivotally connected to the lever intermediate theends thereof and having the other end freely pivotally connected to theother of said web portions.

8. In brake mechanism, a brake drum, brake friction means supportedwithin the drum for engagement with the latter and having spaced endsprovided with radially inwardly extending web portions, actuating meansfor the brake friction means including a lever having a portion at oneend extending at substantially right angles to the radially extendingweb portion at one end of the friction means and slotted to receive aportion of the latter end of said web with the bottom of the slotabutting the edge portion of said end to provide a fulcrum for thelever, said last named web having portions extending at the radiallyinner and outer sides of the right angular end portion of the lever toprevent displacement of the latter relative to the friction means, and alink having a portion at one end extending at substantially right anglesto the web portions and slotted to receive the web on the other end ofthe friction means with the bottom of the slot lengaging a portion ofthe lnner edge of the latter web to provide a fulcrum for the link, saidlast named web also having portions extending along the radially innerand outer sides of the right angular end portion of the link to maintainthe latter in assembled rey lation with the friction means, and aslidable connection between the opposite end of the link and the leverintermediate the ends of the latter.

WRIGHT J. MCCLENAHEN.

